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[19:00:10] ERIN BURNETT, CNN ANCHOR: OUTFRONT tonight, breaking news. We're now learning that the co-pilot who took down Flight 9525 reset the autopilot from 38,000 feet to 100 feet while in flight deliberately setting the plane on a course for disaster.

Plus, more breaking news, investigators scouring the co-pilots home for evidence. What more do we know about Andreas Lubitz. We are live in his hometown tonight. And how did the co-pilot managed to keep the pilot locked out of that cockpit? We're going to show you what he had to do inside the cockpit. Let's go OUTFRONT.

And good evening. I'm Erin Burnett. OUTFRONT tonight, breaking news. Investigators scouring the home of Flight 9525 co-pilot Andreas Lubitz. They are searching for evidence of a motive. Why did Lubitz deliberately crash a commercial jet in the Alps killing 149 innocent people?

Also breaking at this hour, CNN learning Lubitz reprogrammed the plane's autopilot in flight changing the setting from cruising altitude, 38,000 feet to just 100 feet. A premeditated plan condemning everyone on board. This is according to new data from flight radar 24.

And earlier today at one of the most shocking press conferences in memory, prosecutors laid out an incredible sequence of events that they said led to murder. They described the sounds on the cockpit voice recorder including the pilot pounding on the cockpit door yelling to get back inside. Then the passenger screams that filled the plane as 149 people realized what was happening. During it all, the prosecutor says the co-pilot breathed evenly not responding. The co-pilot no one suspected. The airline CEO saying that this co- pilot's record gave absolutely no hint of such horror.

(BEGIN VIDEO CLIP)

CARSTEN SPOHR, CEO, LUFTHANSA (through a translator): He was 100 percent fit to fly without any restrictions. His flight performance was perfect. There was nothing to worry about.

(END VIDEO CLIP)

BURNETT: Our reporters are covering this story tonight from every angle. Fred Pleitgen is in Germany with an exclusive interview with the Lufthansa's CEO. Diana Magnay has new details on the co- pilot. Stephanie Elam is in Phoenix where Lubitz's trained.

And we begin with Rene Marsh with the breaking news on how that plane's auto-pilot was reprogrammed. Rene, you broke this news. And what are you learning about what happened on that auto-pilot?

RENE MARSH, CNN AVIATION CORRESPONDENT: Well, Erin tonight data streamed from Flight 9525 we know suggests that someone manually reprogrammed auto-pilot to bring the jetliner down. Now, flight trafficking website, flight radar 24 tells me they've analyzed data from the plane's transponder and they have determined that someone reprogrammed the auto-pilot from 38,000 feet to just 100 feet. Essentially telling the plane to go down as it continued on a path straight towards the French Alps. As one pilot told me today this manual reprogramming of the autopilot indicates intent to crash this aircraft because 100 feet is below the level of terrain. Erin.

BURNETT: Just horrific. Thank you very much, Rene.

And tonight German officials are trying to everything they can to find out why. Going into the co-pilot's background as they are searching for a reason that could explain why the 28-year-old co-pilot intentionally crashed the plane that would kill everyone on board.

Diana Magnay is OUTFRONT in Montabaur, Germany where the co-pilot Andreas Lubitz lived. Diana, we saw investigators leaving with boxes of evidence from Lubitz's home. What did you see? What are they looking for?

DIANA MAGNAY, CNN CORRESPONDENT: That's right. Investigators at his flat in Duesseldorf and at his parents' house down the road behind me where he grew up and where he still lived from time to time hauling out boxes, anything that they can sift from him his computer records, for example, that could give some kind of indication as to why he did what he did and what exactly his psychological state was that made him bring that plane down. Let's take a look.

(BEGIN VIDEOTAPE)

MAGNAY (voice-over): What we know of the life of Andreas Lubitz gives almost no hint of the man who would deliberately crash a jet liner into a mountainside.

UNIDENTIFIED WOMAN: If one person kills himself and also 149 people, in other words should not be used suicide.

MAGNAY: He seemed to live a normal life. He was accepted into Lufthansa's pilot training program in 2008 training in Germany and Phoenix, Arizona. He joins Germanwings in September, 2013. At the time of the crash 630 hours of flight to experience. Only about 100 in an A-320, the plane he crashed. Lufthansa there says, his flight performance was perfect. There is one flag on his resume.

UNIDENTIFIED WOMAN: There was an interruption with regard to the training.

[19:05:06] MAGNAY: That interruption is said to have lasted several months. Something Lufthansa says it's not uncommon. Police removed evidence from the home where Lubitz's lived with his parents in the German town of Montabaur. No one was willing to speak. But at the nearby flight club where Lubitz was a member, those who knew him describe a happy young man who loved to fly.

UNIDENTIFIED MAN: He was a lot of fun even though he was perhaps sometimes a bit quiet. He was just another boy like so many others here.

MAGNAY: Lubitz's portrait on social media is unremarkable. He ran a Lufthansa half-marathon. He liked night clubs and popular music. There are reports he may have had a girlfriend. But there is one vital piece of information about Andreas Lubitz that we do not know.

SPHOR: We can only speculate about motives. We have no findings at all with regard to why the co-pilot did that.

(END VIDEOTAPE)

MAGNAY: And Erin, the Lubitz's parents traveled must say alongside other grieving families this morning thinking they were going to mourn the loss of their son and then these revelations. You can only imagine what they must be feeling now also alongside the grieving of everyone else -- Erin.

BURNETT: Just impossible to imagine how they must feel. Thank you very much, Diana.

OUTFRONT now our panel of experts, they will be with us throughout the hour. We have aviation correspondent Richard Quest. Former FAA safety inspector David Soucie. Commercial pilot Anthony Roman and Jim Clemente, retired profiler with the FBI.

Richard, the press conferences today were shocking. Usually, a press conference, I don't mean to be light here but they're often designed to give you as little information as they can while being accurate. The French prosecutor here, this was deliberate attempt, this was the co-pilot. Suicide is not the right word. Using the word murder talking about killing 149 of the people. What did you make of these press conferences?

RICHARD QUEST, CNN AVIATION CORRESPONDENT: I was sitting just there in the studio. It was extraordinary because coming to the day with the New York Times report overnight. And we didn't know whether that was true. No disrespect to the Times but we come in with us all ready to say --

BURNETT: And this was the report. The pilot was locked out of the cockpit. That's all we knew.

QUEST: So, we came into the day thinking we've got to be prepared to roll back on this. We've have to be prepared to go in the opposite direction. And then the prosecutor starts and then you have the CEO comes out and says I'm speechless. We have to tell you that the aircraft has been crashed by one of our own pilots. BURNETT: Yes, I mean, they did not mince words. They were not

afraid to say it.

DAVID SOUCIE, FORMER FAA SAFETY INSPECTOR: That's what was so amazing with how this was handled with such stark contrast in any of the other accident we've had. The way it's been handled from the beginning, the way that the prosecutor gave his representation preliminary report. Before he knew this information, they have been very factual as in keeping with the German tradition. It's very, very tactful and very informative. We know everything we need to know.

BURNETT: As we try to understand what happened, I mean, they are desperately now searching for clues about what could be a motive. All right? Motive being the crucial, this man no one seems to have anything. There's no trail on social media. There's nothing. You've investigated plane crash for almost 20 years. Have you heard of a pilot doing something like this?

SOUCIE: Not a pilot. I did have an accident one time. It was a small airplane where it was very, very controlled and this person had planned out his on suicide taken a hammer, rented the airplane with the pilot, took a hammer and then did his deed and intentfully drove it down. That was many years ago, 25 years ago. I'm trying to put this together because that one I was personally involved with. There's other ones that I wasn't. But how could this happen? And it's so different than anything else. This methodical, you have to wonder if maybe this generation has a different thought process about how those go or a different effect on how the environment is affecting them and how they think.

BURNETT: I mean, Jim, because when you are looking at what this individual prosecutors say he did, it wasn't just that he decided to commit suicide and murder 149 people at the same time. It was that he purposely reset the auto-pilot and then he took ten minutes to do it. He didn't go in a dive. It was slow. It was planned. It was controlled. People are screaming worried about dying and he is sitting there in silence continuing. What could possibly explain that?

JIM CLEMENTE, RETIRED FBI PROFILER: Well, clearly it was a deliberate act and he had plenty of time to undo that if he actually wanted to. But this is a suicide, a grandiose suicidal gesture. He wanted to do it in a much bigger way than just taking himself out. He wanted to do it in way that actually took the lives of all the passengers whose lives he was responsible for. So, it was clear that if he would just trying to do this on the spur of the moment that he had plenty of time to unthink that, to undo this and actually stop it. But clearly, he was dedicated to doing this, very determined.

[19:10:03] BURNETT: And Anthony, from what we know today, how premeditated does this plan seem to be? I mean, obviously he reset the auto-pilot. He did not care about the screams that he heard about the pounding on the door. At the same time, this all seemed based upon, that the pilot got up to go to the bathroom which it doesn't seem he would have known what had happened. It's a short flight. In a sense, it seems premeditated and in the other sense it seems he seized this moment because the opportunity arose.

ANTHONY ROMAN, LICENSED COMMERCIAL PILOT: Well, it's very difficult to tell whether it was premeditated or he had suicidal ideation or criminal ideation or religious ideation or some type of labor dispute which was annoying him and came to ahead as he was thinking about it. Very difficult to say, you know, really what his state of mind was. But people know. This was not a secret. His friends knew, his colleagues knew. They knew bits and pieces of anomaly. Something that was a little odd. Something that was a little off. I'm uncomfortable with this about him but I don't think it's dangerous.

BURNETT: Right.

ROMAN: So, when the investigators start putting all that together, they will have a wonderful composite painting of the full picture of the risk here.

QUEST: And there was always the chance of course, that it was just waiting for the moment.

BURNETT: He was ready and the moment presented itself on this flight.

QUEST: Yes. The captain decides he's not going to go to the bathroom on that leg. Remember, they have already flown the leg from Duesseldorf down to Barcelona. He didn't do it on that one. So, why did he do -- he's obviously the pilot flying on the way back up again. But then he gave him point, the captain could have said I'm going to the bathroom or I'm not. This is what so inexplicable about the behavior, a premeditated or pre-thought perhaps but it relying on the opportunity of being able to execute his plan.

BURNETT: And yet, they are being able to withstand the ten minutes of the pounding on the door and then the passengers. He heard, he knew what he was doing. He could hear them.

SOUCIE: You couldn't do that without being mentally removed somehow. It's just -- there's something about the disconnect. There's something about this disassociation with this situation with what's happening at some point. Because this calm breathing. You picture that.

BURNETT: That's what they could hear. They could hear the calm breathing that made them say he was not ill, he was not incapacitated.

SOUCIE: Exactly. Exactly. Very, very strange situation.

BURNETT: All right. Well, thanks to all of you. I know you're staying with us.

Next, we'll going to go inside an airbus A-320. We'll show you the cockpit door that was switch, the pilot used to keep people out of the cockpit. That is to save lives. But what happens when it's the passengers who need protection from the pilots.

Plus, officials say, the co-pilot interrupted his pilot training. That could be crucial. Why?

And outside the cockpit, the pilot frantically pounding on the door. Could he have gotten back inside? We'll going to show you the door and how it works. We'll be right back.

(COMMERCIAL BREAK)

[19:16:40] BURNETT: Breaking news on Flight 9525. Tonight, we are learning that the co-pilot responsible for killing 149 people on board according to prosecutors reprogrammed the plane's autopilot to crash. He changed the cruising altitude from 38,000 feet to just 100 feet. This is according to flight radar 24. Officials say, the cockpit voice recorder indicates that the co-pilot 28-year-old Andreas Lubitz locked the captain out. He then ignored screaming and pounding of the cockpit door putting the plane into that steady descent and crashing it into a mountain. So, how was this pilot able to pull off this horrific act?

Kyung Lah is OUTFRONT.

(BEGIN VIDEOTAPE)

KYUNG LAH, CNN CORRESPONDENT (voice-over): He cannot imagine why a pilot would do this. Bugs Forsythe (ph) knows how. A retired military and commercial pilot, Forsythe says, he's flown thousands of ours in the A-320 cockpit. One of the safest, high-tech passenger jet used around the world.

BUGS FORSYTHE, FORMER COMMERCIAL PILOT: Normal, lock and unlock.

LAH: He, like all pilots has used the switch hundreds of times.

FORSYTHE: The unlock you have to pull up and hold it. A light comes on and says the door is open. But if I release it, it goes back to normal position.

LAH: Norm means it's locked.

FORSYTHE: The norm is locked.

LAH: According to an airbus operations video there's a key pad entry on the outside that allows entry if you know the code. But if the person inside the cockpit switches it to lock, the key pad won't work for five minutes. And there's another override that goes beyond five minutes.

FORSYTHE: I can also override the key pad and hold it in the lock position and now he cannot use the key pad or enter the door at all. It's locked.

LAH: No one can get in?

FORSYTHE: No one can get in.

LAH: So, to keep your co-pilot out, what do have to do? FORSYTHE: You have to keep them out, if they knew this, the

keyboard pad number to get in. I just hold the lock. He cannot get in.

LAH: So, can you manually fly this and hold the lock button?

FORSYTHE: Easy.

LAH: But then that's a very purposeful act?

FORSYTHE: Very much so. Very much so. Pull up.

LAH: Again and again we fly through scenarios, in autopilot, in manual, both managed to crash the plane and both had to be deliberately programmed or flown into the ground.

(on camera): What does that suggest to you as far as his determination?

FORSYTHE: That he was very determined. Yes. That was his goal. He had a mission or a goal to kill himself and everybody on board. We deal with terrorists and people that aren't supposed to be in the cockpit. The person isn't supposed to be in the cockpit, that's what's scary.

LAH (voice-over): A hundred and fifty people lost in this air disaster. The who, the how we now know. The why, far from known.

(END VIDEOTAPE)

LAH: What is so clear after being in the simulator and so chilling after doing this path that the plane took is how much time he had. How much time he had to think about it. How many alarms went off? How many warnings he had and how easily he could have reversed course -- Erin.

BURNETT: That's incredible tragedy. Thank you very much, Kyung Lah. And really Kyung showing you how that cockpit is designed to be safe from a hijacker. From someone who wants to get in keeping those pilots safe. So, how was the co-pilot able to keep the captain out of the cockpit?

Let's go to Stephanie Elam from an airbus A-320 itself, because Stephanie, you're also, you're on the other side here from that pilot who was trying to get in and then he came up against that reinforced door.

STEPHANIE ELAM, CNN CORRESPONDENT: Right, Erin. We're inside of a cockpit like the A-320. And as you can see, you have the door right here. You can see it's a slim door. You've got this peephole. So, you could even see outside as a pilot. But I want to go outside because I want to show you more about this door. Let's take a look.

And when you get outside and take a look at this door, you can see just how thick it is. This is one of those changes that came along after 9/11. One of those things to make this door indestructible to make it solid and hard to break through, there's other ways though. You've also got the lock up here that the pilot could use to lock somebody out as well. And if you take a look at the door from the outside, you can see there's not a lot of ways to get in there. There's like key there, there's like key pad that you just heard Kyung Lah talking about. But overall, not a lot of ways to get in there if the pilot wants to keep you out. And that's the key thing here. This door is all about keeping bad people out, but there's nothing about this door that helps if the person who is going to be detrimental to the plane is actually one of the pilots -- Erin.

[19:21:08] BURNETT: And so, the bottom-line it seems like Stephanie, there's no way that I would imagine towards the end they are trying to break down that door, hit that door with anything, it's going to withstand all of that, right?

ELAM: Yes, that's the idea behind these doors. It's just to make them so impervious, to make it so that you couldn't get through. There's nothing a pilot can do on the outside of this. If you take a look, even, you know, besides the fact of how strong this door is and there's not a lot of ways to compromise it, there's also cameras out here too. So, the pilot inside can see who is out there. Everything is geared towards protecting the pilots inside. Everything about this door is built that way.

BURNETT: Everything about that door, everything about the system as you saw from Stephanie and Kyung. Thank you very much, Stephanie. And our aviation experts are back. David Soucie, Anthony Roman, Richard Quest in New York, in New Orleans, retired FBI profiler Jim Clemente.

David, we have now seen how the system was created from both on the inside of the door with Kyung, the outside of the door with Stephanie showing how it's so fortified. Main question I have for you, after 9/11 in the United States, all the doors had to be fortified like this. So, you know, in those last few minutes when that pilot is doing anything he can to try to save the lives of everyone onboard. You know, they would be taking a fire extinguisher hitting it, they would be doing anything they could to break in.

SOUCIE: Right.

BURNETT: Would this plane have had the fortified doors that American planes had?

SOUCIE: Yes, it would have. Because this was an -- came out for the manufacturers. So, it was dealt with, through the manufacturer --

BURNETT: So, the matter is, where this plane is in the world that's going to have that door?

SOUCIE: That's correct. If it was against an airlines specifically, we wouldn't have seen that or even specific country who is saying you have to do this in our country, that wouldn't have happened, but this is for the manufacturer. And the certification process was very extensive. In fact the regulations for this that that door has to with stand a grenade. BURNETT: A grenade.

SOUCIE: Yes.

BURNETT: And this plane was a 1990 model plane. It would have been retrofitted.

SOUCIE: Yes, it would have certainly.

BURNETT: So, Anthony, you just saw Stephanie show how strong that door is, and you have David describing it, would you agree that even at that moment, a few minutes from impact when they're doing anything they humanly can to try to save their lives, there would be no way to break it down?

ROMAN: It was very little they can do with anything at all. It's a ballistic door. It can handle large explosions, metal piercing bullets. They were doomed.

BURNETT: Jim, what is going on in the mind of the pilot do you think in those moments? He first knocks on the door, the co-pilot doesn't responds, so he thinks he doesn't hear him. Right? You know, it just seems just a mistake and then even seconds passed and he realized something is terribly wrong.

CLEMENTE: I'm sure it was confusion at first because he didn't expect this to happen but then he would first be thinking about his responsibility to the passengers. All those people on his ship they're lives he's responsible for. I'm sure though that as the seconds wound down that he was thinking about the people that he loved, his family and friends and the tragedy that was about to happen to all the people behind him. So, I'm sure it was a terrible time for him even though he was making heroic efforts to try to break that door down which unfortunately was put there to protect him.

BURNETT: And Richard, I think everyone watching and reading this story is just wondering if there was anything that could have been done to stop it. So, a question I have for you is, they don't have a flight data recorder yet. But you know, Rene Marsh is reporting from flight radar that they are able to determine that he set the auto- pilot from 38,000 feet to 100 feet.

QUEST: Yes.

BURNETT: So, they're able to determine that, it would seem like a lot of that was just nobody was looking because nobody would expect it but they might have known at the time it was happening but they wouldn't have been able to do anything.

QUEST: Nobody could do anything at all. The data that Rene Marsh is talking about has to be extracted. So, it's not like --

BURNETT: It's not like it's feeding in real-time --

QUEST: No. You have to go it right into the data. If you look at the outline lines of code which it where it comes from. It's in the -- you have to really look for it. What you have here is, David's experienced this, you have a situation that was created in terms of 9/11. Then there was a solution. And now, there's another problem as a result of that solution. And it just keeps elevating the issue. Because this whole thing was designed to stop somebody getting in, but somebody has to fly the plane. A pilot, a human being has the fly it. So now you've got the issue of how do you deal with it if the person on the inside has gone rogue. And this is the balancing act that constantly has to be taking place in the aviation industry.

BURNETT: All right.

SOUCIE: That's what safety is.

BURNETT: And it's hard because you program it now for something that happens and you keep doing that.

ROMAN: But there's a simple solution.

SOUCIE: Yes.

ROMAN: There's a simple solution and the United States has introduced that simple solution. You introduce a second person into the cockpit during the time.

BURNETT: Right. So, if you go to the bathroom, someone else comes in.

ROMAN: Absolutely.

BURNETT: All right.

ROMAN: No one should be alone.

[19:26:02] BURNETT: All right. Thanks to all of you. You'll be back.

OUTFRONT next, the co -pilot trained in Germany and the United States in Arizona. But we found out he took an extended break during his training. Why? We are live tonight outside that training facility. And our exclusive interview with the CEO of Lufthansa. The man who said, suicide is not the right word to use for this horrific act.

(COMMERCIAL BREAK)

[19:30:19] BURNETT: Breaking news: police at this hour hunting for new clues as to why the co-pilot of Flight 9525 took that plane down. Today, they searched his apartment, as well as his parents' home, looking for any hint of a possible motive.

At the same time, we're learning a little bit more about the 28- year-old, including his time spent in the United States.

Sara Sidner is on the ground in Phoenix tonight. That is where the co-pilot did some of his flight training.

And, Sara, what have you been able to learn about how long he was in the United States? Why he was here? What he was doing?

SARA SIDNER, CNN CORRESPONDENT: Well, we know from a spokesperson with Lufthansa that we had a conversation with that there was training. It was here in Arizona. The co-pilot did come here to train.

You can see over my right shoulder some of the Lufthansa planes that are used for training here. We know he had to be here for six months because according to the spokesperson, that six months is required for him to get his license and fly for Lufthansa.

So, that is the reason why he was here. He came here for work. And you might wonder why Arizona? Why would you have to come here from Germany?

Arizona is home to a lot of training facilities, and one of the reasons is because you don't have the weather issues that the rest of the world generally deals with. They have open skies. You can train almost every day of the year.

We do not know from the facility itself exactly where he trained. They are not speaking to us today. But we know they have their flags flying at half staff. It's the German flag, a Lufthansa flag, a KLM flag, all flying at half staff here today, obviously, in memory of those who have lost their lives in this terrible tragedy.

But we do know that he came here to train as do other pilots from around the world -- Erin.

BURNETT: Sara, I guess the question I have is he was there for six months because that's the length of the training program but he didn't do that consecutively. He took a break in the middle of his training. That obviously could be hugely significant.

At this time, do you have any idea as to why he took that break?

SIDNER: You know, that's one of the questions that investigators are really trying focus in on and figure out. We do not know the why. We know, according to the CEO, that he did take a break in his training. We don't know if he took break in training here, if he took a break in the training in Germany.

But we know that eventually he finished, and he was 100 percent ready to go according to the CEO. He passed medical tests. He had passed all of his technical tests and that he was a full fledged pilot and ready to take the reins. So, we've got to figure out and the investigators have to figure out what that is and if that has any link to any other issues he may have been having, which may have caused him to do what investigators think he may have down which is down the plane -- Erin.

BURNETT: All right. Thank you very much, Sara.

And Fred Pleitgen is OUTFRONT. He's in Cologne, Germany, tonight. Fred, you spoke exclusively with the CEO of Lufthansa today. A

man who is in complete and utter shock, describes himself as speechless. Were you able to get any insight from him, as to the motive? As to what might have caused the co-pilot to do what they say he did?

FREDERIK PLEITGEN, CNN SENIOR INTERNATIONAL CORRESPONDENT: Well, you know, it's a interesting because he says he has no explanation for it. He said one of the things that Lufthansa has prided itself on is the fact they are so good at evaluating their pilots. He said we always managed to pick the best people, to train them in the best possible way.

And he also said that there are checks in place to see whether people are mentally fit to fly aircraft. They go through a rigorous process. They have to go through assessment centers, where they have to do multi-tasking operations under very hard duress, to make sure that they don't collapse under difficult situations. So, he said it's unclear how all of this could have happened.

Let's listen in to what he had to say.

(BEGIN VIDEO CLIP)

CARSTEN SPOHR, CEO, LUFTHANSA: The pilot passed all his tests, all his medical exams. We have at Lufthansa, a reporting system where crew can report without being punished their own problems or they can report about problems of others without any kind of punishment. That hasn't been used either in this case. So, all the safety nets, all the safety nets we're so proud of here have not worked in this case.

(END VIDEO CLIP)

PLEITGEN: But he does say he still does believe in those safety checks that they have. He says they have been working for Lufthansa for the past decades. But he also acknowledged that in light of what happened with Andreas Lubitz doing what he did, that they are going to re-evaluate to see if they have to do more to see whether their pilots are mentally fit to fly, Erin.

BURNETT: All right. Fred Pleitgen, thank you very much with that interview from Cologne.

All right. Richard Quest is with me. So, this break in his training -- at this point, obviously, they're grasping at anything they can because people didn't seem to see this coming.

[19:35:03] That break could be significant.

RICHARD QUEST, CNN AVIATION CORRESPONDENT: Yes, German newspapers, there's a rumor in German newspapers, "Ders Spiegel", that says some neighbor said he was down and may have been depressed. We have not gotten confirmation on that. But that is one of the things that is out there that in Germany tonight.

BURNETT: And so, the CEO of Lufthansa said, all the safety nets we're so proud of here have not worked in this case. We've just heard him say it. That's terrifying. He said this pilot was 100 percent, 100 percent fit, 100 percent ready. Obviously, if he did this, it was the opposite.

Are pilots going through real psychological set of testing or not?

QUEST: No. They get into a psychological test when they're given a job. And thereafter, you know, it's part of an assessments. In the U.S., questions are asked of them. But elsewhere --

BURNETT: I mean, how hard are the questions? Have you felt like killing yourself and felt down? I mean --

(CROSSTALK)

QUEST: Absolutely.

BURNETT: One knows if one says yes, you'll not get the job.

QUEST: Absolutely. It's those sort of things.

I think you have to bear in mind, Carsten Spohr is a man who's been at Lufthansa.

BURNETT: That's the CEO.

QUEST: Yes, he's been in Lufthansa all his life. He's a pilot himself. He's only been CEO a couple of years, you know, 18 months.

Many people in the industry tonight, Erin, they are like people who suddenly been told the world is flat. Something that has happened elsewhere in the world or an odd case, but not of major airline like Lufthansa that suddenly finds a young, first officer has basically committed mass murder. They are absolutely, the industry, I can tell you is in shock over this.

BURNETT: A complete shock.

And in Arizona, two of the 9/11 hijackers trained there. And after that, they added in extra scrutiny for foreigners training in the U.S.

Would that have meant anything the case?

QUEST: No, I mean, he not only trained, he passed. He got his certification from the FAA. Arizona is the home along with Florida of air training. Now, we do not -- we cannot, it's inexplicable the even that have happened over the last few days.

BURNETT: All right. Richard Quest, thank you.

And next, FBI is now involved, looking at his background, from his medical history, to his religion. What inspired him to do this?

And officials calling the crash of Flight 9525 eerily similar to the Egypt Air murder/suicide that happened soon after take off from JFK. This isn't the first time a pilot has deliberately taken down a full passenger jet.

(COMMERCIAL BREAK)

[19:41:22] BURNETT: The FBI is now involved into the investigation into the co-pilot Andreas Lubitz. U.S. intelligence analysts are looking into links of terrorism.

And our justice reporter Evan Perez is OUTFRONT.

And, Evan, the FBI now involved. What are they looking for?

EVAN PEREZ, CNN JUSTICE CORRESPONDENT: Well, Erin, they're in a support role here. But, you know, they have a lot of stuff they can do, which is to look through any communications that they can access if this co-pilot used any U.S. e-mail services, for instance.

You know, there's also a role for the NSA and intelligence services. There's a lot of controversy over in Europe about the fact that NSA scoops up a lot of communications in Europeans in just the normal course of what they do.

And I bet that right now the German investigators are pretty happy that the NSA might have some of this stuff, because what they want to look at is to see if there's anything that can show up, you know, from recent communications perhaps in the last month or couple of days that might shed light on his mental state or if he's been in contact with anybody that the U.S. is concerned about.

BURNETT: And, Evan, there are a lot of questions. I was just talking about this with Richard and Sara and with Fred about the gap in his flight training.

PEREZ: Right.

BURNETT: Obviously, we know six months of that took place in the United States.

PEREZ: Right.

BURNETT: Richard reporting -- talking about an unsubstantiated report in German newspapers that there was depression, again, unsubstantiated at this point.

Will the FBI be able to shed anymore light on that, on what could be very, very crucial thing?

PEREZ: Well, yes. The mental state is definitely what they're interested in. Going to that flight training center in Arizona is something the FBI plans to do, to try to interview anybody who might have had any contact with him, anybody who was perhaps training him to see if they can say whether he showed any signs back then and whether there were any red flags missed because that is definitely one of the questions that investigators, even German airline wants to know now, which is was there something they missed that clearly led to this. BURNETT: All right. Evan Perez, thank you very much.

And OUTFRONT again, the retired FBI profiler, Jim Clemente.

Jim, you know, what's amazing here is how little we know about the co-pilot. He had a social media existence. He liked to go to disco. He ran marathons. We don't know really anything.

There are reports he had a girlfriend but we don't know who she is. If he did, where she's from? We know nothing.

Do you think personal issues are a likely motive?

JIM CLEMENTE, RETIRED FBI PROFILER: Yes, I think in the case that's the only thing. There are no indications of anything else. But what needs to be done, what the FBI will be conducting along with the other investigators is what's called a psychological autopsy, where they go in and they try to find out, they break him down psychologically and find all the different parts of his life, whether relationships, broken relationship, family, friends, interests.

All that stuff will come into play and they will build a picture of what he's really like inside his head.

BURNETT: So, Jim, the prosecutor today, the word used was emphatically. He emphatically refused to comment on the co-pilot's religion. Is that relevant? Either his religion all together, people ask that question for obvious reasons, or is it relevant that they won't comment?

CLEMENTE: It's relevant in as much as it's part of the psychological autopsy. We have to know what his beliefs are. What his faith is in, what it isn't in.

And I think what they were just trying to do is bring it away from automatically thinking that he was a particular religion which has terroristic ties, and so on and so forth.

BURNETT: Right.

CLEMENTE: I think that's what they're trying to avoid until they know.

BURNETT: All right. So, possible motives. You've got religion, you've got politics, you've got personal issues, workplace anger. At this point, does -- do any of those seem more likely than another to you?

CLEMENTE: Well, I think right now, I think we're talking about personal issues. I think he's 28 years old. That age he's not -- you know, he's an adult but he's not a really experienced adult.

[19:45:02] I think what you're looking at is probably something to do with relationships in his life, either a broken relationship or a relationship he couldn't have, that he wanted. And I think he went out in a grandiose way to prove himself bigger than everybody thought he was.

BURNETT: All right. Jim Clemente, thank you very much.

CLEMENTE: You're welcome.

BURNETT: And OUTFRONT next, the crash of Flight 9525 bears striking similarity to another commercial crash, intentionally crash by a pilot. We have a report.

And breaking news, Saudi fighter jets pounding Yemen with airstrikes. Is the Mideast on the verge of a major war?

(COMMERCIAL BREAK)

BURNETT: Breaking news in the tragic crash of 9525. CNN has learned the co-pilot reprogrammed the plane's auto pilot settings during the flight, changing the plane's altitude from cruising at 38,000 feet to just 100 feet, intentionally setting it on a deadly path. That's according to new data from Flight Radar 24.

This isn't the first time a fatal crash of commercial airliner is blamed on a captain or co-pilot.

Shasta Darlington is OUTFRONT.

(BEGIN VIDEOTAPE)

SHASTA DARLINGTON, CNN CORRESPONDENT (voice-over): As investigators piece together the final moment of Flight 9525, already, there are haunting similarities to EgyptAir flight 990.

October 1999, the Boeing 767 departed JFK Airport in New York. Minutes later, plunging into the waters off the coast of Massachusetts.

[19:50:01] CONTROLLER 1: I lost contact with the Boeing 767 in my airspace.

CONTROLLER 2: The EgyptAir?

CONTROLLER 1: Yes, I mean, we lost radar. We lost everything.

DARLINGTON: Moments before the crash, the captain left the cockpit to use the bathroom. The voice recorder captured co-pilot Gameel al-Batouti repeating in Arabic, "I rely on God." No emergency call transmitted.

Egyptian authorities say it was a mechanical failure. A rejection of the National Transportation Safety Board's conclusion, the co-pilot intentionally crashed the plane. In many countries, pilots have to prove their mental health for their license. But throughout their careers, airlines mostly rely on self-diagnosis.

LES ABEND, BOEING 777 CAPTAIN: We police ourselves as colleagues. If we know that we're having stress at home, we may want to just call in sick for that trip. DARLINGTON: When a Silk Air flight crashed in 1987, killing all

104 people on board, the Boeing 737 fell so fast it broke the speed of sound. Indonesian authorities ruled out suicide but the NTSB said a deliberate crash was the likely cause. Citing that the cockpit voice recorder was intentionally disconnected and controls set to nose down position.

Less than a year and a half ago, a scorched trail of smoldering debris, visible after Mozambique Airlines Flight 470 went down in Namibia, killing all 33 people aboard. Officials calling it a deliberate crash by the pilot.

And then, there's Malaysia Airlines Flight 370. After more than a year of searching and investigating, what happened to the plane is still a mystery.

Pilot suicide one of the many theories floated as the cause of its disappearance.

(END VIDEOTAPE)

BURNETT: And, Shasta, what's amazing is that after all of these incidents, there is still no real mental health screening. There is nothing rigorous other than some, as Richard was saying, some questions. You know, do you have suicidal thoughts, where you know the answers would be.

DARLINGTON: Exactly. And what pilots have been saying is that while they don't see an epidemic of suicidal tendencies in pilots, there really needs to be more monitoring, more accompanying, not only physical health but of mental health long after they've passed that initial background check and the initial evaluations. That really isn't happening in most countries.

BURNETT: Right. I mean, in this case, I mean, we really just don't know what happened at this point, but it's supposedly could have been something to do with depression. That's one possibility. It also could have been something more psychopathic, which again, none of that was picked up on screening and some of those cases, those are people who are very skilled at evading detection.

DARLINGTON: Exactly. This is where the investigation will go now. And it's really turning into less of a technical investigation and more of a personal investigation, a criminal investigation of this co-pilot.

BURNETT: All right. Shasta, thank you very much.

And OUTFRONT next, breaking news. Saudi fighter jets pounding Yemen with air strikes, the region on the verge of a major war. Hundreds of thousands of ground troops massing. A live report next.

(COMMERCIAL BREAK)

[19:56:56] BURNETT: Breaking news. Saudi warplanes now pounding Yemen with 150,000 ground troops ready to invade. It's a huge number and it's a new front in the Middle East war with major implications for America.

Right now, Yemen is in chaos, allowing ISIS and al Qaeda to flourish.

Barbara Starr is at the Pentagon tonight.

And, Barbara, this is not just Saudi Arabia. There are nine other Middle Eastern countries involved. I mean, it's huge. Not just Americans but Arabs. This is a big deal, isn't it?

BARBARA STARR, CNN PENTAGON CORRESPONDENT: It is. Good evening, Erin.

These are the Sunni Arab nations that are growing increasingly nervous in the all-important Persian Gulf about the growth of Iran's influence. Iran now backing those Shia Houthi rebels in Yemen. So, on one side, Iran's influence.

The Saudi Arabia backing the beleaguered Yemen government and U.S. somewhat also stepping into this right now. As those war planes continue, and Saudi Arabia builds a coalition of other Sunni Arab nations, the U.S. military at the orders of the White House jumping in with some assistance, intelligence sharing from satellites, offering assistance on aerial refueling, even offering assistance on mission planning to plan those aerial strike missions.

You're seeing a lot of damage on the ground inside of Yemen. The potential for large numbers of civilian casualties, but the Saudis are very nervous. This has put Iran right on their doorstep and is posing a real problem in the region. Nerves and tensions definitely growing, Erin.

BURNETT: Of course, Iran, yes, has been the other side of this so in a lot of ways, have a crucial proxy war going on. When you talk about the United States involvement, though, Barbara, the United States fighting this war against ISIS, but the president resolutely saying no ground troops are going to go in.

Will the United States consider troops or air strikes in this case given how crucial Yemen is to counterintelligence and how significant ISIS and al Qaeda are there?

STARR: I think at this point the answer would likely be that the administration would not want to do that.

In fact, we know that right now, as the U.S. offers that aerial refueling, the aerial intelligence, no manned aircraft over Yemen. It is very dicey airspace right now. The Saudis partially conducting these airstrikes so they can control the airspace. The worry is the Houthi rebels now have their hands on weapons and aircrafts and this becomes very difficult.

So, the Saudis trying to reestablish some military control in the air. Unlikely to see the U.S. go in, they really want to make this, you know, the new policy is make the nations in the region take the front line responsibility. Offer help, offer assistance, but that they are going to have to do the heavy lifting themselves -- Erin.

BURNETT: Barbara, thank you. Pretty incredible though when you think about it. Saudi Arabia putting 150,000 troops on the border, ready to invade, something I think a lot of people thought would never happen. And it is happening now, a very significant development in the fight against ISIS and al Qaeda.

Thank you so much for joining us. Be sure to set your DVR to record OUTFRONT so you can watch us at anytime, any day. I'll be back here same time tomorrow night.